Load-carrying apparatus, assemblies, and subterranean drilling systems may include a support ring with a plurality of contact elements coupled to the support ring. The plurality of contact elements may have a surface exhibiting a partially cylindrical shape.

Bearing assemblies that include a plurality of polycrystalline diamond (“PCD”) bearing elements, bearing apparatuses including such bearing assemblies, and methods of operating and fabricating such bearing assemblies and apparatuses are disclosed. In an embodiment, the plurality of PCD bearing elements of one or more of the bearing assemblies disclosed herein include at least one first PCD bearing element. At least a portion of the first PCD bearing element exhibits a coercivity of about 125 Oersteds or more and a specific magnetic saturation of about 14 Gauss.Math.cm.sup.3/gram or less. The first PCD bearing element includes a bearing surface with at least one groove formed therein. In an embodiment, the plurality of PCD bearing elements also include at least one second PCD bearing element. The second PCD bearing element exhibits a coercivity that is less than and a specific magnetic saturation that is greater than the first PCD bearing element.

A liquid hammer drill comprising: a housing; a drill bit at a leading end of said housing wherein said drill bit includes a trailing end and a leading end that defines a cutting portion; a piston member located inside said housing and having a trailing end, a leading end and an intermediate portion therebetween, said piston member being capable of movement between a first position and a second position at which it impacts the trailing end of the drill bit; a liquid circuit for delivering a liquid to the piston member to cause the piston member to oscillate between its first and second positions and transfer the liquid outside the housing via a liquid outlet; a sealing member for isolating the trailing end of the drill bit from the liquid circuit wherein, in use, the piston member impacts the trailing end of the drill bit in a liquid free environment.

A tool for building a wellbore includes a tool body with a flow passage extending axially therethrough, a piston chamber formed radially through the tool body that intersects the flow passage of the tool body, a piston disposed in the piston chamber, at least one actuation element that exerts a force between the piston and the piston chamber, and a sleeve disposed within the flow passage of the tool body that includes at least one cutout. When the sleeve is in a first position within the tool body, the cutout is axially offset from the piston, and when the sleeve is in a second position, the cutout is axially aligned with the piston.

Bearing assemblies, apparatuses, systems, and methods include bearing assemblies where one of the bearing assemblies may include bearing surfaces defining an at least partially conical inner surface.

A flow control device includes a stack of annular discs positioned in a flow path. Each disc includes fluid passageways extending between inner and outer perimeters of the disc, with each passageway defining a flow axis extending out of the disc and radially offset from a central axis of the discs. A plug is moveable relative to the discs between closed and open positions. In the closed position, a cylindrical section of the plug is positioned to block fluid flow through the annular discs. In the open position, the annular discs and a tapered section of the plug collectively define an annular vortex chamber. The fluid passageways in the annular discs and the tapered section of the plug collectively impart a rotational flow when the plug is in the open position and as fluid exits the annular discs.

Methods of manufacturing a radial sliding bearing may include coupling superhard contact elements to support rings where each superhard contact element includes a superhard contact surface and forming at least some of the superhard contact surfaces to comprise an arcute or a planar surface.

A rotary actuator assembly can include a fluid motor with a rotor that displaces with hypocyclic precessional motion within a stator in response to fluid flow through the fluid motor, and a gear reducer section including an input gear that is fixed relative to the rotor and displaces with the hypocyclic precessional motion relative to an output gear. Another rotary actuator assembly can include a fluid motor with a rotor having a central longitudinal axis that rotates about a central longitudinal axis of a stator, and a gear reducer section including an input gear that rotates with the rotor and displaces relative to an output gear, and the input gear having the same central longitudinal axis as the rotor. A well system can include at least two fluid motors, and fluid flow through one fluid motor causes rotation of the other fluid motor in the well.

The present invention provides a reaming tool, comprising a channel body having a tubular wall and comprising a dynamic sleeve and a fluid channel across the center of the channel body. There are two or more tubular, drive chambers stacked one after another, and surrounded by a torsional housing having separate segments allowing fluid flow and jetting impact on each segment, each drive chamber having one or more inlet(s) upstream for fluid entry and one or more discharge holes downstream for fluid discharge. A stabilized housing is coupled around the torsional housing and one end of the stabilized housing rotatably coupled with the dynamic sleeve of the channel body, and another end of the stabilized housing is a reamer head having one or more fluid outlet.

Methods, systems, and apparatus for imparting and limiting hypocycloidal, lateral, and torsional forces onto drill bits are provided, including hypocycloidal bearings for limiting hypocycloidal motion, lateral impulse mechanisms for imparting lateral movement to a drill bit, and torsional impulse mechanisms for imparting torsional movement to a drill bit. The methods systems, and apparatus may decrease friction, increase drilling efficiency, and provide additional benefits to drilling systems.